1. Field of the Invention
The invention relates to a self-propelled agricultural harvesting machine, in particular, a self-propelled field chopper, with an attachment or implement for picking up cut crop lying on a field or grassland, such as grass/hay or green forage, or for harvesting corn, and similar stalked crop, in the field. The harvesting machine comprises a processing device for chopping and/or processing the harvested crop and an unloading device arranged downstream thereof and formed substantially of a curved unloading spout for picking up the harvested crop from the processing device at a pick-up location and for transferring the harvested crop to a drop location on a transport vehicle. The harvesting machine also has a drive device embodied as a drive motor whose operating speed is adjustable by a control device to an idle speed or nominal speed.
2. Description of the Related Art
Such agricultural harvesting machines are employed in combination with different attachments for harvesting grass/hay as well as for harvesting corn. The drive action is generally realized by means of a drive motor in the form of an internal combustion engine whose operating speed can be adjusted either to idle speed or a nominal so that the drive motor of the self-propelled agricultural harvesting machine can be operated only with the nominal speed when working.
A self-propelled agricultural harvesting machine is described in German Democratic Republic patent document DD 200 234. A controlled adjustment is said to be obtained according to a current load situation by reducing the operating speed of the drive motor used during working when transporting the device because the transport of the device requires a reduced power in comparison to its working situation. For this purpose, the speed of the drive motor is reduced for the transport to a constant value below the nominal speed so that the drive motor operates within a more favorable range with reduced fuel consumption. The speed reduction is to be initiated by an impulse which is generated when switching on the transport gear. However, the self-propelled agricultural harvesting machine will be operated over the course of its service life and use predominantly in the working state, i.e., at nominal speed, so that the fuel savings during transport of the harvesting machine relative to the total fuel consumption during the entire service life and use will constitute only a fraction of the total. Of much greater importance in this connection is the configuration and operation of the self-propelled agricultural harvesting machine with different attachments or implements.
For harvesting grass, the self-propelled agricultural harvesting machine is provided with an attachment or implement for picking up crop stalks, such as grass/hay and green forage, laid in swaths, wherein the working width of the attachment or implement is configured such that transport of the self-propelled agricultural harvesting machine with the implement attached is still within legal limits. This means that the width of the implement matches thus approximately the transportation width limit of self-propelled agricultural harvesting machines on public roads.
In order to obtain an acceptable output per surface unit when harvesting corn (maize), it is necessary to provide the self-propelled agricultural harvesting machine within an implement whose working width corresponds at least to a multiple of the transportation width limit of the harvesting machine on public roads. Based on this, different lateral lengths or distances result during operation of the harvesting machine between the self-propelled agricultural harvesting machine and a transport vehicle driving adjacent thereto; the transport vehicle serves for receiving and transporting the chopped harvested crop.
For ensuring a loss-free transfer of the harvested crop, the unloading device, in the form of a curved spout, is configured, as a function of the width of the attachment or implement, to have different lengths between a pick-up location, where the unloading device picks up the harvested crop from a processing device of the self-propelled agricultural harvesting machine, and a drop location of the harvested crop on a transport vehicle driving next to the harvesting machine. In practice, it was found that in the case of self-propelled agricultural harvesting machines, which are designed, based on their maximum installed motor power, for use with an implement with a large working width (corn or maize harvesting attachment) and a long spout, the maximum drive power provided by the drive motor cannot be utilized in the case of an attachment with smaller working width for cutting grass and a short spout so that in this way a portion of the provided drive power remains unused and the self-propelled agricultural harvesting machine cannot be used in an economical way when used for harvesting grass.
It is an object of the present invention to overcome the disadvantages of the prior art and to configure a self-propelled agricultural harvesting machine such that an economical use can be achieved for the different power levels required for harvesting grass/hay or corn.
In accordance with the present invention, this is achieved in that the drive motor, during operation of the harvesting machine with an implement of a large working width and with a great distance between the pick-up location and the drop location of the curved spout, is operated in the range of the nominal speed and, during operation with an implement with minimal working width and with a minimal distance between the pick-up location and the drop location of the curved spout, is operated in a speed range which is reduced relative to the nominal speed.
In a self-propelled agricultural harvesting machine according to the invention, it is proposed, for optimizing the ratio between the usable motor power and the fuel consumption required for the useable motor power in the case of harvesting grass as well as harvesting corn, to operate the drive motor of the self-propelled agricultural harvesting machine in the range of the nominal speed during operation with an attachment of a great working width (several times greater than the transport width of the harvesting machine) and a great distance between the pick-up location and the drop location of the curved spout, while the drive motor can be operated in a speed range which is reduced relative to the nominal speed during operation with an attachment of minimal working width and a minimal distance between the pick-up location and the drop location of the curved spout. In this way, it is achieved according to the invention that the self-propelled agricultural harvesting machine, in particular, a self-propelled field chopper, can be operated at maximum power of the drive motor when harvesting corn while the drive motor can be operated at a reduced speed in an operating state with reduced motor power for harvesting grass. As can be seen in power curves of drive motors, in this range the specific fuel consumption drops also so that in this way the absolute fuel consumption, which is calculated based on the specific fuel consumption and the motor power consumed at this operating point, can be significantly lowered. The driver/operator of the self-propelled agricultural harvesting machine can therefore utilize the harvesting machine under optimal economical conditions even for harvesting grass.
According to a simple and thus cost-beneficial embodiment of the invention it is proposed that a control device, provided for setting the operating speed of the drive motor of the self-propelled agricultural harvesting machine during operation, is formed by a switching device which serves for adjusting the motor speed to idle speed or the nominal speed and for adjusting at least one speed reduced relative to the nominal speed. This means that the driver/operator of the self-propelled agricultural harvesting machine can select by actuation of a switching devicexe2x80x94preferably an electric or electronic devicexe2x80x94the operating speed based on the employed implement and the distance between the pick-up location of the harvested crop from a processing device and the drop location of the harvested goods onto the transport vehicle so that the harvesting machine is operated under optimal conditions for harvesting grass as well as corn.
According to a further advantageous aspect of the invention it is conceivable to embody the control device for setting the operating speed of the drive motor such that the reduction of the motor speed is carried out as a function of the distance between the pick-up location of the harvesting crop from the processing device into the curved spout and the drop location of the harvested crop onto the transport vehicle. For this purpose, sensors (sensing means) can be provided which detect this distance and transmit it to the control device so that an automatic controlled reduction of the operating speed relative to the nominal speed can be achieved. Preferably, the area of the reduced speed can be within a range of approximately 75% to 85% of the nominal speed.